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Hematopoietic stem cell transplantation (HSCT) is a cornerstone of modern medical practice, and can only be performed safely and effectively with appropriate transfusion medicine support. Patients undergoing HSCT often develop therapy-related cytopenia, necessitating differing blood product requirements in the pre-, peri-, and post-transplant periods. Moreover, ensuring optimal management for patients alloimmunized to human leukocyte antigens (HLA) and/or red blood cell (RBC) antigens, as well as for patients receiving ABO-incompatible transplants, requires close collaboration with transfusion medicine and blood bank professionals. Finally, as updated transfusion guidelines and novel blood product modifications emerge, the options available to the transplant practitioner continue to expand. Herein, we detail contemporary blood transfusion and transfusion medicine practices for patients undergoing HSCT.

Python for Population Genomics (PyPop) is a software package that processes genotype and allele data and performs large-scale population genetic analyses on highly polymorphic multi-locus genotype data. In particular, PyPop tests data conformity to Hardy-Weinberg equilibrium expectations, performs Ewens-Watterson tests for selection, estimates haplotype frequencies, measures linkage disequilibrium, and tests significance. Standardized means of performing these tests is key for contemporary studies of evolutionary biology and population genetics, and these tests are central to genetic studies of disease association as well. Here, we present PyPop 1.0.0, a new major release of the package, which implements new features using the more robust infrastructure of GitHub, and is distributed via the industry-standard Python Package Index. New features include implementation of the asymmetric linkage disequilibrium measures and, of particular interest to the immunogenetics research communities, support for modern nomenclature, including colon-delimited allele names, and improvements to meta-analysis features for aggregating outputs for multiple populations. Code available at: https://zenodo.org/records/10080668 and https://github.com/alexlancaster/pypop.

Precise typing of human leukocyte antigens (HLA) is crucial for clinical hematopoietic stem cell and solid organ transplantations, transfusion medicine, HLA-related disease association, and drug hypersensitivity analysis. The UCLA Cell Exchange program has played a vital role in providing educational and proficiency testing surveys to HLA laboratories worldwide for the past 5 decades. This article highlights the significant contribution of the UCLA Cell and DNA Exchange Programs in advancing HLA antibody testing, genotyping, crossmatches, and, more recently, virtual crossmatches. Additionally, we discuss future directions of the UCLA Cell Exchange program to support histocompatibility testing to adapt to the fast-evolving field of immunotherapy, tolerance and xenotransplantation.

Introduction: The prevalence of gluten-related disorders, mainly celiac disease (CD) and non-celiac gluten sensitivity (NCGS), varies between 0.6% and 13% in the general population. There is controversial evidence regarding the association of both CD and NCGS with extra-digestive manifestations, including recurrent reproductive failure (RRF), which may have clinical implications. Objective: To study the prevalence of HLA susceptibility alleles for CD/NCGS in a cohort of female patients with RRF from a single reference center and to evaluate the effect of a gluten-free diet on reproductive success. Material and methods: A retrospective study was conducted on 173 patients with RRF, consecutively attended at the Reproductive Immunology Unit of San Carlos University Clinical Hospital in Madrid. We collected and analyzed the clinical, analytical, and immunological profiles of RRF patients who presented HLA alleles associated with CD and NCGS (HLA DQ2.2, DQ2.5, DQ8, and DQ7.5). Results: We observed a significantly higher prevalence of HLA alleles associated with CD and NCGS in our RRF cohort compared to the prevalence in the general population (69% vs. 35%–40%, p<0.0001). Only 2.3% of patients met the criteria for a CD diagnosis. In our RRF cohort, HLA-genetic susceptibility for CD/NCGS (HLA-risk group) was associated with a significantly higher rate of hypothyroidism compared to patients without these alleles (HLA-negative group) (48.7% vs. 26.92%, p=0.03). Patients with HLA-genetic susceptibility for CD/NCGS and thyroid disease had a significantly higher success rate in the subsequent pregnancy after management (55% vs. 30%, p=0.002). Two factors were found to be significant in this group: a gluten-free diet (p=0.019) and the use of levothyroxine (p=0.042). Conclusions: In our cohort of RRF patients, we observed a significantly higher prevalence of HLA susceptibility genes for CD/NCGS compared to the general population, also associated with a higher incidence of thyroid alterations. A gluten-free diet and the use of levothyroxine in cases of thyroid pathology had significant beneficial effects on pregnancy outcomes. We suggest that HLA typing for CD/NCGS and a gluten-free diet, in the presence of risk alleles, can improve pregnancy outcomes in RRF patients. [ABSTRACT FROM AUTHOR]

Introduction: Modern histocompatibility algorithms depend on the comparison and analysis of high-resolution HLA protein sequences and structures, especially when considering epitope-based algorithms, which aim to model the interactions involved in antibody or T cell binding. HLA genotype imputation can be performed in the cases where only low/intermediate-resolution HLA genotype is available or if specific loci are missing, and by providing an individuals' race/ethnicity/ancestry information, imputation results can be more accurate. This study assesses the effect of imputing high-resolution genotypes on molecular mismatch scores under a variety of ancestry assumptions. Methods: We compared molecular matching scores from "ground-truth" highresolution genotypes against scores from genotypes which are imputed from low-resolution genotypes. Analysis was focused on a simulated patient-donor dataset and confirmed using two real-world datasets, and deviations were aggregated based on various ancestry assumptions. Results: We observed that using multiple imputation generally results in lower error in molecular matching scores compared to single imputation, and that using the correct ancestry assumptions can reduce error introduced during imputation. Discussion: We conclude that for epitope analysis, imputation is a valuable and low-risk strategy, as long as care is taken regarding epitope analysis context, ancestry assumptions, and (multiple) imputation strategy. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: The aim of this work was to explore molecular amino acids (AAs) and related structures of HLA-DQA1-DQB1 that underlie its contribution to the progression from stages 1 or 2 to stage 3 type 1 diabetes. Methods: Using high-resolution DQA1 and DQB1 genotypes from 1216 participants in the Diabetes Prevention Trial-Type 1 and the Diabetes Prevention Trial, we applied hierarchically organised haplotype association analysis (HOH) to decipher which AAs contributed to the associations of DQ with disease and their structural properties. HOH relied on the Cox regression to quantify the association of DQ with time-to-onset of type 1 diabetes. Results: By numerating all possible DQ heterodimers of α- and β-chains, we showed that the heterodimerisation increases genetic diversity at the cellular level from 43 empirically observed haplotypes to 186 possible heterodimers. Heterodimerisation turned several neutral haplotypes (DQ2.2, DQ2.3 and DQ4.4) to risk haplotypes (DQ2.2/2.3-DQ4.4 and DQ4.4-DQ2.2). HOH uncovered eight AAs on the α-chain (−16α, −13α, −6α, α22, α23, α44, α72, α157) and six AAs on the β-chain (−18β, β9, β13, β26, β57, β135) that contributed to the association of DQ with progression of type 1 diabetes. The specific AAs concerned the signal peptide (minus sign, possible linkage to expression levels), pockets 1, 4 and 9 in the antigen-binding groove of the α1β1 domain, and the putative homodimerisation of the αβ heterodimers. Conclusions/interpretation: These results unveil the contribution made by DQ to type 1 diabetes progression at individual residues and related protein structures, shedding light on its immunological mechanisms and providing new leads for developing treatment strategies. Data availability: Clinical trial data and biospecimen samples are available through the National Institute of Diabetes and Digestive and Kidney Diseases Central Repository portal (https://repository.niddk.nih.gov/studies). [ABSTRACT FROM AUTHOR]

Summary No risk factors have been identified for vaccine‐induced immune thrombotic thrombocytopenia (VITT) so far. The aim of this study was to identify human leucocyte antigen (HLA) alleles potentially associated with VITT susceptibility. Specific HLA class II alleles were detected with significantly higher frequency in VITT patients compared with Italian controls: DPB1*17:01, DQA1*05:01, and DRB1*11:04. In silico analysis revealed increased affinity of DRB1*11:04 for a platelet factor 4 (PF4)‐derived peptide, ITSLEVIKA, that contains two amino acids present in the specific binding site of anti‐PF4 antibodies from VITT patients. Our findings show for the first time a genetic predisposition to developing anti‐PF4 antibodies in response to Ad‐vector vaccines. [ABSTRACT FROM AUTHOR]

Cytotoxic CD8+ T lymphocytes (CTLs) have been implicated in the severity of COVID-19. The TCR-pMHC ternary complex, formed by the T cell receptor (TCR) and peptide-MHC (major histocompatibility complex), constitutes the molecular basis of CTL responses against SARS-CoV-2. While numerous studies have been conducted on T cell immunity, the molecular mechanisms underlying CTLmediated immunity against SARS-CoV-2 infection have not been well elaborated. In this review, we described the association between HLA variants and different immune responses to SARS-CoV-2 infection, which may lead to varying COVID-19 outcomes. We also summarized the specific TCR repertoires triggered by certain SARS-CoV-2 CTL epitopes, which might explain the variations in disease outcomes among different patients. Importantly, we have highlighted the primary strategies used by SARS-CoV-2 variants to evade T-cell killing: disrupting peptide-MHC binding, TCR recognition, and antigen processing. This review provides valuable insights into the molecule mechanism of CTL responses during SARS-CoV-2 infection, aiding efforts to control the pandemic and prepare for future challenges. [ABSTRACT FROM AUTHOR]

Background: Humanized mice transplanted with CD34+ hematopoietic cells (HPCs) are broadly used to study human immune responses and infections in vivo and for testing therapies pre-clinically. However, until now, it was not clear whether interactions between the mouse major histocompatibility complexes (MHCs) and/or the human leukocyte antigens (HLAs) were necessary for human T-cell development and immune reactivity. Methods: We evaluated the long-term (20-week) human hematopoiesis and human T-cell development in NOD Scid Gamma (NSG) mice lacking the expression of MHC class I and II (NSG-DKO). Triplicate experiments were performed with HPCs obtained from three donors, and humanization was confirmed in the reference strain NOD Rag Gamma (NRG). Further, we tested whether humanized NSG-DKO mice would respond to a lentiviral vector (LV) systemic delivery of HLA-A*02:01, HLA-DRB1*04:01, human GM-CSF/IFN-α, and the human cytomegalovirus gB antigen. Results: Human immune reconstitution was detectable in peripheral blood from 8 to 20 weeks after the transplantation of NSG-DKO. Human single positive CD4+ and CD8+ T-cells were detectable in lymphatic tissues (thymus, bone marrow, and spleen). LV delivery harnessed the detection of lymphocyte subsets in bone marrow (αβ and γδ T-cells and NK cells) and the expression of HLA-DR. Furthermore, RNA sequencing showed that LV delivery increased the expression of different human reactome pathways, such as defense responses to other organisms and viruses. Conclusions: Human T-cell development and reactivity are independent of the expression of murine MHCs in humanized mice. Therefore, humanized NSG-DKO is a promising new model for studying human immune responses, as it abrogates the xenograft mouse MHC interference. [ABSTRACT FROM AUTHOR]

Crimean–Congo hemorrhagic fever virus (CCHFV) belongs to Nairoviridae family and has tripartite RNA genome. It is endemic in various countries of Asia, Africa, and Europe and is primarily transmitted by Hyalomma ticks but nosocomial transmission also been reported. Vaccines for CCHF are in early phase of clinical trial; therefore, this work is centered on identification of potential immunogenic peptide as vaccine candidates with application of different immunoinformatics approaches. Eleven conserved (>90%) peptides of CCHFV nucleoprotein were selected for CD8+ T‐cell (NetMHCpan 4.1b and NetCTLpan 1.1 server) and CD4+ T‐cell (NetMHCIIpan‐4.0 server and Tepitool) epitope prediction. Three peptides containing multiple CD8+ and CD4+ T‐cell and B‐cell epitopes were identified on basis of consensus prediction approach. Peptides displayed good antigenicity score of 0.45–0.68 and predicted to bind with diverse human leukocyte antigen (HLA) alleles. Molecular docking was performed with epitopes to HLA and HLA‐epitopes complex to T‐cell receptor (TCR). In most of the cases, docked complex of HLA‐epitope and HLA‐epitopes‐TCR have the binding energy close to respective natural bound peptide complex with HLA and TCR. Molecular dynamic simulation also revealed that HLA‐peptide complexes have minimum fluctuation and deviation than HLA‐peptide‐TCR docked over 50 ns simulation run. Considering these findings, identified peptides can serve as potential vaccine candidates for CCHFV disease. [ABSTRACT FROM AUTHOR]

Background and Objectives Study Design and Methods Results Conclusion Accurate human leucocyte antigen (HLA) and human platelet antigen (HPA) typing is essential for establishing a blood platelet donor bank to deal with refractoriness in patients undergoing multiple platelet transfusions. Current methods, such as Sanger and next‐generation sequencing, encounter difficulties in haplotyping. Herein, the aim of this study was to establish a method for HLA and HPA typing based on the long read sequencing.The HPA and HLA class I genotypes of 268 platelet donors from the Taiyuan Blood Center, China were identified using long‐read sequencing on the PacBio platform. Allele frequencies for HPA systems and HLA class I genes were calculated, and genetic variability within HPA system genes was analysed.Polymorphisms were identified in 8 of the 35 HPA systems (HPA‐1 to HPA‐6w, HPA‐15 and HPA‐21w), with the frequencies of the ‘b’ allele at 0.0187, 0.0709, 0.4086, 0.0075, 0.0149, 0.0317, 0.4310 and 0.0019, respectively. The alleles with the highest frequencies at the HLA‐A, HLA‐B and HLA‐C loci are HLA‐A02:01, B51:01, B46:01 and C06:02, respectively. Additionally, several genetic patterns in HPA systems were identified, including the c.166‐1029C>T variant, which was found exclusively in samples carrying the HPA‐1b allele.This study developed a targeted long‐read sequencing method characterized by high throughput and simultaneity, capable of resolving allele ambiguities for effective HLA class I genotyping in establishing a platelet donor bank. [ABSTRACT FROM AUTHOR]

BK polyomavirus infection is an important cause of graft loss in transplant patients, however, currently available therapies lack effectiveness against this pathogen. Identification of immunological targets for potential treatments is therefore necessary. The aim of this study was to predict candidates of immunodominant epitopes within four BK virus proteins (VP1, VP2, VP3 and LTA) using PBMCs from 44 healthy donors. We used the ELISpot epitope mapping method to evaluate the T‐cell response, and HLA‐peptide binding was predicted using the NetMHCpan algorithm. A total of 11 potential peptides were selected for VP1, 3 for VP2/VP3 and 13 for LTA. Greater reactivity was observed for VP1 and LTA proteins compared with VP2/VP3. Most of the peptides selected as potential immunodominant candidates were restricted towards several HLA class I and II alleles, with predominant HLA class I binding by computational predictions. Based on these findings, the sequences of the selected immunodominant epitopes candidates and their corresponding HLA restrictions could contribute to the optimisation of functional assays and aid in the design and improvement of immunotherapy strategies against BK virus infections. [ABSTRACT FROM AUTHOR]

Foetal cells are detectable in women decades postpartum, a state termed foetal microchimerism. The interplay between these semi‐allogeneic foetal cells and the mother could be affected by genetic mismatches in the HLA loci. Here, we relate HLA allele and molecular mismatch values to the presence and quantity of foetal microchimerism in the maternal circulation during pregnancy and postpartum. A total of 76 pregnant women were included, of which 59 were followed up 1–8 years postpartum. Maternal and foetal DNA was genotyped for HLA class I and II loci. Foetal cells in maternal buffy coat were detected by qPCR, targeting inherited paternal alleles. Antibody‐verified eplet mismatch and Predicted Indirectly Recognisable HLA Epitopes (PIRCHE) scores were calculated to quantify foetal‐maternal histocompatibility from the mother's perspective. Circulating foetal cells were detected in 50.0% (38/76) of women during pregnancy, and 25.4% (15/59) postpartum. During pregnancy, HLA class II antibody‐verified eplet mismatch load and PIRCHE scores correlated negatively with the presence and quantity of foetal cells in the maternal circulation. Postpartum, HLA class I allele mismatches correlated negatively with foetal microchimerism presence, while HLA class II allele mismatches, HLA class I and II antibody‐verified eplet mismatch load, and PIRCHE‐I and PIRCHE‐II scores correlated negatively with both microchimerism presence and quantity. The correlation between mismatch parameters aimed at evaluating the risk of humoral and T cell‐mediated allorecognition and foetal microchimerism was more evident postpartum than during pregnancy. The observed predictive effect of foetal‐maternal histocompatibility on foetal microchimerism suggests that circulating foetal cells are subject to clearance by the maternal immune system. We propose that allorecognition of foetal cells in the maternal circulation and tissues influences any long‐term effect that foetal microchimerism may have on maternal health. [ABSTRACT FROM AUTHOR]

Selecting compatible HLA‐Class I and/or HPA platelets based on genotyping could alleviate immune platelet transfusion refractoriness (PTR). A fast and reliable method of HLA‐Class I and HPA genotyping is necessary to construct a platelet donor bank with known HLA‐Class I and HPA genotypes. Ten pairs of specific primers for HLA‐A, HLA‐B, HLA‐C, HPA‐1 through HPA‐6w, HPA‐15 and HPA‐21w were designed. The appropriate fragments were optimised for amplification in a single multiplex reaction. After a cleanup step using paramagnetic beads, the amplicon library was prepared and sequenced. To validate the accuracy of the developed method, commercial NGS kits for the genotyping of HLA‐A, HLA‐B and HLA‐C and the TaqMan real‐time PCR method in‐house for the genotyping of HPA‐1 through HPA‐6w, HPA‐15 and HPA‐21w were used to detect all the specimens in parallel. A total of 386 specimens were detected and the results of genotyping HLA‐A, HLA‐B, HLA‐C and HPA‐1 through HPA‐6w, HPA‐15 and HPA‐21w were obtained simultaneously, which is 100% consistent between the two methods. Four new HLA alleles, HLA‐A*11:451, HLA‐A*30:01:26, HLA‐B*39:201 and HLA‐B*40:538, were also reconfirmed. Two novel SNVs, c.2671C > T and c.2681T > G, in the coding region of ITGA2B were detected, all of which are heterozygous in individuals. A novel NGS method based on multiplex PCR was established to detect HLA‐Class I and HPA simultaneously, which is high‐throughput, rapid and accurate and could be applied to build a platelet donor bank. [ABSTRACT FROM AUTHOR]

Killer‐cell immunoglobulin‐like receptor (KIR) interactions with HLA class I have crucial roles in modulating NK cell function in response to viral infections. To explore the correlation between KIR/HLA and susceptibility to SARS‐CoV‐2 infection, we analysed polymorphism of KIR genes, haplotypes, HLA allotypes, and the interplay between KIR and HLA in individuals diagnosed with COVID‐19. Compared to a population control group, we observed a significantly increased frequency of KIR3DL3*00802 in the COVID‐19 group. When encoded by the HLA‐B gene, the frequency of HLA‐Bw4, a ligand for KIR3DL1, was at lower frequency in the COVID‐19 group. Additionally, significantly elevated frequencies of KIR‐Bx3, KIR3DL3*00301, 3DL3*048, and C1+HLA‐C were identified in the COVID‐19 group before multiple test correction, suggesting associations with susceptibility to SARS‐CoV‐2 infection. Our findings indicate that the KIR3DL3*00802 allele may be a high‐risk factor for SARS‐CoV‐2 infection, while Bw4 encoded by HLA‐B gene may confer protective effects against the infection. [ABSTRACT FROM AUTHOR]

Eplet 52SK is unique in the HLA eplet registry as targeting the whole family of DQA1*01 alleles. It is proposed as an antibody‐verified eplet but has not been validated enough to deserve this label. Especially, confusion can occur with reactivity targeting the 52PQ eplet which is present on the DQB1*05 and DQB1*06 alleles families, as DQ molecule stability imposes DQA1*01 to selectively associate with these DQ‐β families only. Using two Luminex single antigen (LSA) assays from two vendors, beads bearing DR‐α/DQ6 heterodimers, a special build LSA panel of additional DQ beads, and an adsorption/elution strategy relying on cells from deceased donors or recombinant cells solely expressing one DQ antigen, we definitely established the antibody‐verified status of eplet 52SK using patients' sera reacting only against the DQ5 and DQ6 beads of the One Lambda LSA panel in routine patients' follow up. We also show that reactivity against this eplet is not a rare event among anti‐DQ1 immunisation. This study further strengthens the importance of considering the DQA1 locus in immunological studies of HLA and in organ allocation strategies. [ABSTRACT FROM AUTHOR]

Immune dysregulation has been observed in individuals with sleep disturbance, with HLA molecules play a crucial role in the immune response. This study aimed to investigate the associations between HLA alleles and sleep behaviours, considering several environmental factors. Data were sourced from the UK Biobank. Logistic regression analyses were performed to explore the associations between 359 HLA alleles and 4 sleep behaviours, including chronotype (n = 204,636), insomnia (n = 227,553), snoring (n = 214,350) and daytime dozing (n = 227,197). Furthermore, gene‐environmental interaction studies (GEIS) were conducted to evaluate the interactions of HLA alleles with environmental factors on sleep behaviours. This study analysed a total sample and subgroups stratified by sex to elucidate the impact of HLA alleles on sleep behaviours. Our findings revealed several associations between specific HLA alleles and sleep behaviours. Notably, HLA‐A*23:01 was associated with evening chronotype in the total sample (OR = 0.918, 95%CI: 0.872–0.965), while HLA‐A*32:01 was associated with evening chronotype in males (OR = 1.089, 95%CI: 1.037–1.144). Furthermore, GEIS identified multiple sets of interactions associated with sleep behaviours. For example, the interaction of HLA‐DPA1*01:04 with alcohol consumption was associated with daytime dozing in the total sample (OR = 1.993, 95%CI: 1.351–2.941), while the interaction of HLA‐DQB1*05:04 with ever suffered mental distress preventing usual activities was associated with insomnia in males (OR = 0.409, 95%CI: 0.254–0.658). Our findings highlight the involvement of HLA in sleep regulation and underscore the potential interactions between HLA alleles and environmental factors in modulating susceptibility to sleep behaviours. [ABSTRACT FROM AUTHOR]

Regulatory agencies such as the Food and Drug Administration (FDA) and the European Medicines Agency (EMA) recognize pharmacogenetics as a key tool in their pharmacological guidelines for pharmaceutical counseling. In this context, community pharmacies play a crucial role in addressing this healthcare need, which could lead to a significant improvement in patients' quality of life by preventing ineffective or contraindicated treatments. In this work, we conducted a systematic review of the available scientific evidence regarding druggene interactions relevant to community pharmacy. We identified the main genes and polymorphisms associated with treatment response and adverse effects in primary care. Finally, we propose a model for implementing pharmacogenetic services in community pharmacies. [ABSTRACT FROM AUTHOR]

Objective: To establish a method for detecting the binding affinity of peptides to HLA-B*1301 by HLA molecular reconstitution after weak acid treatment, and its practicality was evaluated. Methods: C1R cells overexpressing HLA-B*1301 were treated with citrate buffer of different pH for different time. After neutralization of pH, cells were resuspended in culture medium containing β2m and brefeldin A. Cells were incubated at 37 °C with peptide (peptide group) or without peptide (blank control), after addition of anti-HLA antibody, the cells were detected by flow cytometry. Ratio of fluorescence intensity between peptide group and blank control group was used as an index to measure the level of HLA molecular remodeling, and then represented the interactions between peptide and HLA-B*1301 molecule. Results: HLA-polypeptide complex was denatalized and dissociated after being treated with pH3.0 buffer for 1 min, and only HLA heavy chain molecules were retained on the cell surface. The addition of peptides with binding force could significantly improve the level of HLA molecular remodeling, and the binding force of peptides with HLA-B*1301 could be evaluated by this method. Conclusion: HLA molecular reconstitution assay is a simple and reliable method to detect the binding of peptides to HLA-B*1301, which can also provide reference for the study of other low frequency HLA molecular antigen presentation patterns. [ABSTRACT FROM AUTHOR]

Objective: To establish a method for detecting the binding affinity of peptides to HLA-B*1301 by HLA molecular reconstitution after weak acid treatment, and its practicality was evaluated. Methods: C1R cells overexpressing HLA-B*1301 were treated with citrate buffer of different pH for different time. After neutralization of pH, cells were resuspended in culture medium containing β2m and brefeldin A. Cells were incubated at 37 °C with peptide (peptide group) or without peptide (blank control), after addition of anti-HLA antibody, the cells were detected by flow cytometry. Ratio of fluorescence intensity between peptide group and blank control group was used as an index to measure the level of HLA molecular remodeling, and then represented the interactions between peptide and HLA-B*1301 molecule. Results: HLA-polypeptide complex was denatalized and dissociated after being treated with pH3.0 buffer for 1 min, and only HLA heavy chain molecules were retained on the cell surface. The addition of peptides with binding force could significantly improve the level of HLA molecular remodeling, and the binding force of peptides with HLA-B*1301 could be evaluated by this method. Conclusion: HLA molecular reconstitution assay is a simple and reliable method to detect the binding of peptides to HLA-B*1301, which can also provide reference for the study of other low frequency HLA molecular antigen presentation patterns. [ABSTRACT FROM AUTHOR]

Background: In this study, prenatal and postnatal blood samples were taken from pregnant women who had 35 or more gestational weeks and had not developed anti‐HLA positivity yet. The aim of this study was to evaluate the factors that may be effective in the development of panel reactive antibody (PRA) positivity during pregnancy. Methods: PRA testing was studied by taking the blood of 86 pregnant women 1 month before birth. Blood was taken again 1 month after birth from these women with prenatal PRA negative and it was checked whether PRA positivity developed. As a control group, 40 women without pregnancy were selected for the study. Results: Of the 86 pregnant, 42 (48.8%) had cesarean sections, 44 (51.2%) had normal births, and PRA positivity developed in 14 (32.5%) of cesarean deliveries and three (8.0%) of normal births. In the control group, there were three (7.5%) PRA positivity. A statistically significant difference was found between cesarean delivery, normal delivery, and control group. Moreover, when compared with the control group, it was found statistically significant that all deliveries increased the development of HLA Class II antibodies. Discussion: Cesarean delivery was associated with increased PRA positivity compared to normal birth. The new information presented in this study will pave the way for further research and enable healthcare professionals to consider both the individual's potential future need for organ transplantation and the positive impact on public health and more effective management of healthcare costs when making decisions regarding cesarean section. [ABSTRACT FROM AUTHOR]

The Human Leukocyte Antigen (HLA) system contains a set of genes involved at many levels in the innate and adaptive immune response. Among the non-classical HLA class I genes, HLA-G stands out for the numerous studies about its pivotal role in regulating/modulating immune responses. Also, its involvement in extravillous cytotrophoblast function, viral infections, autoimmunity, and cancer has been extensively documented. The present study explores for the first time the relationship between natural alleles of HLA-G, rather than STSs, SNPs, or partial gene polymorphisms, and the development of gastric adenocarcinoma, by analyzing the genetic profile of a cohort of 40 Spanish patients with this type of tumor using DNA extracted from paired biopsies of tumoral and adjacent non-tumoral gastric tissue. Our results reveal a significant statistical relationship between the presence of the HLA-G*01:01:01 allele and the development of gastric cancer, while other common alleles such as -G*01:04 or -G*01:05N did not demonstrate a significant correlation. Studying the involvement of HLA genes in the development of many diseases is relevant to understanding their pathophysiology. However, the absence of specific mechanisms underlying these associations suggests that investigating complete HLA natural alleles' extended haplotypes or complotypes may offer a more precise and valuable approach to elucidating the association of HLA with the pathogenesis of disease. [ABSTRACT FROM AUTHOR]

Epstein-Barr virus (EBV) infection has been advocated as a prerequisite for developing multiple sclerosis (MS) and possibly the propagation of the disease. However, the precise mechanisms for such influences are still unclear. A large-scale study investigating the host genetics of EBV serology and related clinical manifestations, such as infectious mononucleosis (IM), may help us better understand the role of EBV in MS pathogenesis. This study evaluates the host genetic factors that influence serological response against EBV and history of IM and cross-evaluates them with MS risk and genetic susceptibility in the Swedish population. Plasma IgG antibody levels against EBV nuclear antigen-1 [EBNA-1, truncated = amino acids (aa) (325–641), peptide = aa(385–420)] and viral capsid antigen p18 (VCAp18) were measured using bead-based multiplex serology for 8744 MS cases and 7229 population-matched control subjects. The MS risk association for high/low EBV antibody levels and history of IM was compared to relevant clinical measures along with sex, age at sampling, and associated HLA allele variants. Genome-wide and HLA allele association analyses were also performed to identify genetic risk factors for EBV antibody response and IM history. Higher antibody levels against VCAp18 [odds ratio (OR) = 1.74, 95% confidence interval (CI) = 1.60–1.88] and EBNA-1, particularly the peptide (OR = 3.13, 95% CI = 2.93–3.35), were associated with an increased risk for MS. The risk increased with higher anti-EBNA-1 IgG levels up to 12× the reference risk. We also identified several independent HLA haplotypes associated with EBV serology overlapping with known MS risk alleles (e.g. DRB1*15:01). Although there were several candidates, no variants outside the HLA region reached genome-wide significance. Cumulative HLA risk for anti-EBNA-1 IgG levels, particularly the peptide fragment, was strongly associated with MS. In contrast, the genetic risk for high anti-VCAp18 IgG levels was not as strongly associated with MS risk. IM history was not associated with class II HLA genes but negatively associated with A*02:01 , which is protective against MS. Our findings emphasize that the risk association between anti-EBNA-1 IgG levels and MS may be partly due to overlapping HLA associations. Additionally, the increasing MS risk with increasing anti-EBNA-1 levels would be consistent with a pathogenic role of the EBNA-1 immune response, perhaps through molecular mimicry. Given that high anti-EBNA-1 antibodies may reflect a poorly controlled T-cell defence against the virus, our findings would be consistent with DRB1*15:01 being a poor class II antigen in the immune defence against EBV. Last, the difference in genetic control of IM supports the independent roles of EBNA-1 and IM in MS susceptibility. [ABSTRACT FROM AUTHOR]

Oxaliplatin is commonly used to treat gastrointestinal malignancies. However, its applications are limited due to potential adverse drug reactions (ADRs), particularly severe anaphylactic shock. There is no method to predict or prevent ADRs caused by oxaliplatin. Therefore, we aimed to investigate the genetic HLA predisposition and immune mechanism of oxaliplatin-induced ADRs. A retrospective review was performed for 154 patients with ADRs induced by oxaliplatin during 2016–2021 recorded in our ADR notification system. HLA genotyping was conducted for 47 patients with oxaliplatin-induced ADRs, 1100 general population controls, and 34 oxaliplatin-tolerant controls in 2019–2023. The in vitro basophil activation test (BAT) was performed and oxaliplatin-specific IgE levels were determined. The incidence of oxaliplatin-induced ADRs and anaphylactic shock in our cohort was 7.1% and 0.15%, respectively. Of the 154 patients, 67.5% suffered rash/eruption; 26.0% of the patients who could not undergo oxaliplatin rechallenge were considered to show oxaliplatin-induced immune-mediated hypersensitivity reactions (HRs). The genetic study found that the HLA-DRB∗12:01 allele was associated with oxaliplatin-induced HRs compared to the general population controls (sensitivity = 42.9%; odds ratio [OR] = 3.4; 95% CI = 1.4–8.2; P = 0.008) and tolerant controls (OR = 12; 95% CI = 2.3–63.7; P = 0.001). The in vitro BAT showed higher activation of CD63+ basophils in patients with oxaliplatin-induced HRs compared to the tolerant controls (P < 0.05). Only four patients (8.5%) with oxaliplatin-induced ADRs were positive for oxaliplatin-specific IgE. This study found that 26.0% of patients with oxaliplatin-induced ADRs could not undergo oxaliplatin rechallenge. HLA-DRB∗12:01 is regarded as a genetic marker for oxaliplatin-induced hypersensitivity. [ABSTRACT FROM AUTHOR]

This paper aims to detect a target that crosses the baseline connecting the source and the receiver in shallow-water environments, which is a special scenario for a bistatic sonar system. In such a detection scenario, an intense sound wave, known as the direct blast, propagates directly from the source to the receiver without target scattering. This direct blast usually arrives at the receiver simultaneously with the forward scattering signal and exhibits a larger intensity than the signal, posing a significant challenge for target detection. In this paper, a range-domain subspace is constructed by the horizontal distance between the source/target and each element of a horizontal linear array (HLA) when the ranges of environmental parameters are known a priori. Meanwhile, a range-domain subspace detector based on direct blast suppression (RSD-DS) is proposed for forward scattering detection. The source and the target are located at different positions, so the direct blast and the scattered signal are in different range-domain subspaces. By projecting the received data onto the orthogonal complement subspace of the direct blast subspace, the direct blast can be suppressed and the signal that lies outside the direct blast subspace is used for target detection. The simulation results indicate that the proposed RSD-DS exhibits a performance close to the generalized likelihood ratio detector (GLRD) while requiring less prior knowledge of environments (only known are the ranges of the sediment sound speed and the bottom sound speed), and its robustness to environmental uncertainties is better than that of the latter. Moreover, the proposed RSD-DS exhibits better immunity against the direct blast than the GLRD, since it can still work effectively at a signal-to-direct blast ratio (SDR) of −30 dB, while the GLRD stops working in this case. [ABSTRACT FROM AUTHOR]

Idiosyncratic drug-induced liver injury (iDILI) by flucloxacillin presents as both cholestatic and hepatocellular injury. Its mechanistic steps are explored in the present analysis as limited data exist on the cascade of events leading to iDILI in patients with an established diagnosis assessed for causality by the Roussel Uclaf Causality Assessment Method (RUCAM). Studies with human liver microsomes showed that flucloxacillin is a substrate of cytochrome P450 (CYP) with ist preferred isoforms CYP 3A4/3A7 that toxified flucloxacillin toward 5′-hydroxymethylflucloxacillin, which was cytotoxic to human biliary epithelial cell cultures, simulating human cholestatic injury. This provided evidence for a restricted role of the metabolic CYP-dependent hypothesis. In contrast, 5′-hydroxymethylflucloxacillin generated metabolically via CYP 3A4/3A7 was not cytotoxic to human hepatocytes due to missing genetic host features and a lack of non-parenchymal cells, including immune cells, which commonly surround the hepatocytes in the intact liver in abundance. This indicated a mechanistic gap regarding the clinical hepatocellular iDILI, now closed by additional studies and clinical evidence based on HLA B*57:01-positive patients with iDILI by flucloxacillin and a verified diagnosis by the RUCAM. Naïve T-cells from volunteers expressing HLA B*57:01 activated by flucloxacillin when the drug antigen was presented by dendritic cells provided the immunological basis for hepatocellular iDILI caused by flucloxacillin. HLA B*57:01-restricted activation of drug-specific T-cells caused covalent binding of flucloxacillin to albumin acting as a hapten. Following drug stimulation, T-cell clones expressing CCR4 and CCR9 migrated toward CCL17 and CCL25 and secreted interferon-γ and cytokines. In conclusion, cholestatic injury can be explained metabolically, while hepatocellular injury requires both metabolic and immune activation. [ABSTRACT FROM AUTHOR]

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It has been demonstrated previously that human leukocyte antigen class I (HLA-I) and class II (HLA-II) alleles may modulate JAK2 V617F and CALR mutation (CALRmut)-associated oncogenesis in myeloproliferative neoplasms (MPNs). However, the role of immunogenetic factors in MPNs remains underexplored. We aimed to investigate the potential involvement of HLA genes in CALRmut+ MPNs. High-resolution genotyping of HLA-I and -II loci was conducted in 42 CALRmut+ and 158 JAK2 V617F+ MPN patients and 1,083 healthy controls. A global analysis of the diversity of HLA-I genotypes revealed no significant differences between CALRmut+ patients and controls. However, one HLA-I allele (C*06:02) showed an inverse correlation with presence of CALR mutation. A meta-analysis across independent cohorts and healthy individuals from the 1000 Genomes Project confirmed an inverse correlation between the presentation capabilities of the HLA-I loci for JAK2 V617F and CALRmut-derived peptides in both patients and healthy individuals. scRNA-Seq analysis revealed low expression of TAP1 and CIITA genes in CALRmut+ hematopoietic stem and progenitor cells. In conclusion, the HLA-I genotype differentially restricts JAK2 V617F and CALRmut-driven oncogenesis potentially explaining the mutual exclusivity of the two mutations and differences in their presentation latency. These findings have practical implications for the development of neoantigen-based vaccines in MPNs. [ABSTRACT FROM AUTHOR]

More than 50 years have elapsed since the association of human leukocyte antigens (HLA) with type 1 diabetes (T1D) was first reported. Since then, methods for identification of HLA have progressed from cell based to DNA based, and the number of recognized HLA variants has grown from a few to tens of thousands. Current genotyping methodology allows for exact identification of all HLAencoding genes in an individual's genome, with statistical analysis methods evolving to digest the enormous amount of data that can be produced at an astonishing rate. The HLA region of the genome has been repeatedly shown to be the most important genetic risk factor for T1D, and the original reported associations have been replicated, refined, and expanded. Even with the remarkable progress through 50 years and over 5,000 reports, a comprehensive understanding of all effects of HLA on T1D remains elusive. This report represents a summary of the field as it evolved and as it stands now, enumerating many past and present challenges, and suggests possible paradigm shifts for moving forward with future studies in hopes of finally understanding all the ways in which HLA influences the pathophysiology of T1D. [ABSTRACT FROM AUTHOR]

Coeliac disease (CD) is an autoimmune disorder caused by the ingestion of gluten-containing grains. One of the prerequisites for the development of the disease is the presence of specific combinations of HLA alleles at the DQA1 and DQB1 loci. The HLA test is a supportive diagnostic test. In the Czech Republic, approximately 3,500 HLA tests for CD diagnosis are performed annually in almost three dozen laboratories. The HLA Department of the Institute of Haematology and Blood Transfusion in Prague has been offering the EPT "Detection of HLA Alleles Associated with Diseases" for more than 10 years. The results are evaluated in terms of the correct determination of predisposing alleles/allelic groups and clinical interpretation. Every year, we notice some problems with the detection of CD-associated alleles and the interpretation of results. Annual workshops are part of this EPT, and they also include recommendations for the interpretation of results. This interpretation is evolving based on the current knowledge in the field. The current recommendation for interpretation was adopted in 2023, dividing HLA-DQA1/DQB1 genotypes into three categories: 1) detected HLA genotype is associated with predisposition to coeliac disease; 2) coeliac disease could not be excluded based on the detected HLA genotype; 3) coeliac disease could be excluded with high probability based on the detected HLA genotype. The quality of examination is increasing but still needs improvement. Correct results and accurate interpretation can inform clinicians' decisions about the diagnosis of coeliac disease in appropriate patients. [ABSTRACT FROM AUTHOR]

To investigate the genetic relationship between end stage renal disease (ESRD) and human leukocyte antigen (HLA) alleles in the Guangxi Zhuang population. We performed polymerase chain reaction reversed sequence-specific oligonucleotide (PCR-rSSO) in 325 patients with ESRD and genotyped the HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 loci. The direct counting method was used to determine the frequencies of HLA alleles, and Arlequin software (version 3.5.2.2) was used for haplotypic frequency analyses to compare the included ESRD patients with 350 healthy donors from the Guangxi Zhuang population. In our study, 120 HLA alleles, 284 HLA-A-B-DRB1 haplotypes, and 332 HLA-A-C-B-DRB1-DQB1 haplotypes were detected. We found that only A*11:01-B*15:02-DRB1*12:02 had a positive association with ESRD (P = 0.001, Pc = 0.020, OR = 3.106, 95% CI = 1.497–6.446) after Bonferroni correction; thus, individuals with this haplotype may be susceptible to ESRD. A*11:01-B*15:02-DRB1*12:02 is a potentially valuable haplotype for evaluating the risk of ESRD in the Guangxi Zhuang population. [ABSTRACT FROM AUTHOR]

The Canary Islands inhabitants, a recently admixed population with significant North African genetic influence, has the highest incidence of childhood-onset type 1 diabetes (T1D) in Spain and one of the highest in Europe. HLA accounts for half of the genetic risk of T1D. Aims: To characterize the classical HLA-DRB1 and HLA-DQB1 alleles in children from Gran Canaria with and without T1D. Methods: We analyzed classic HLA-DRB1 and HLA-DQB1 alleles in childhood-onset T1D patients (n = 309) and control children without T1D (n = 222) from the island of Gran Canaria. We also analyzed the presence or absence of aspartic acid at position 57 in the HLA-DQB1 gene and arginine at position 52 in the HLA-DQA1 gene. Genotyping of classical HLA-DQB1 and HLA-DRB1 alleles was performed at two-digit resolution using Luminex technology. The chi-square test (or Fisher's exact test) and odds ratio (OR) were computed to assess differences in allele and genotype frequencies between patients and controls. Logistic regression analysis was also used. Results: Mean age at diagnosis of T1D was 7.4 ± 3.6 years (46% female). Mean age of the controls was 7.6 ± 1.1 years (55% female). DRB1*03 (OR = 4.2; p = 2.13–13), DRB1*04 (OR = 6.6; p ≤ 2.00–16), DRB1* 07 (OR = 0.37; p = 9.73–06), DRB1*11 (OR = 0.17; p = 6.72–09), DRB1*12, DRB1*13 (OR = 0.38; p = 1.21–05), DRB1*14 (OR = 0.0; p = 0.0024), DRB1*15 (OR = 0.13; p = 7.78–07) and DRB1*16 (OR = 0.21; p = 0.003) exhibited significant differences in frequency between groups. Among the DQB1* alleles, DQB1*02 (OR: 2.3; p = 5.13–06), DQB1*03 (OR = 1.7; p = 1.89–03), DQB1*05 (OR = 0.64; p = 0.027) and DQB1*06 (OR = 0.19; p = 6.25–14) exhibited significant differences. A total of 58% of the studied HLA-DQB1 genes in our control population lacked aspartic acid at position 57. Conclusions: In this population, the overall distributions of the HLA-DRB1 and HLA-DQB1 alleles are similar to those in other European populations. However, the frequency of the non-Asp-57 HLA-DQB1 molecules is greater than that in other populations with a lower incidence of T1D. Based on genetic, historical and epidemiological data, we propose that a common genetic background might help explain the elevated pediatric T1D incidence in the Canary Islands, North-Africa and middle eastern countries. [ABSTRACT FROM AUTHOR]

Summary: Peptide‐binding motif (PBM) model, a hierarchical clustering of HLA class I based on their binding specificity, was developed to predict immunopeptidome divergence. The effect of PBM mismatches on outcomes is unknown in HLA‐haploidentical haematopoietic cell transplantation with post‐transplant cyclophosphamide (PTCy‐haplo). We therefore conducted a retrospective study using national registry data in PTCy‐haplo. Overall, 1352 patients were included in the study. PBM‐A bidirectional mismatch was associated with an increased risk of overall mortality in multivariable analysis (hazard ratio, 1.26; 95% confidence interval, 1.06 to 1.50; p = 0.010). None of relapse, non‐relapse mortality (NRM) and graft‐versus‐host disease showed significant differences according to PBM‐A bidirectional mismatch status in the entire cohort. The impact of PBM‐A bidirectional mismatch on overall survival (OS) was preserved within the HLA‐A genotype bidirectional mismatch population, and their lower OS stemmed from higher relapse rate in this population. The worse OS due to high NRM with PBM‐A bidirectional mismatch was prominent in lymphoid malignancies receiving reduced‐intensity conditioning. The PBM model may predict outcomes more accurately than HLA genotype mismatches. In conclusion, this study demonstrated that the presence of PBM‐A bidirectional mismatch elevated the risk of mortality of PTCy‐haplo. Avoiding PBM‐A bidirectional mismatch might achieve better outcomes in PTCy‐haplo. [ABSTRACT FROM AUTHOR]

The human leukocyte antigen (HLA) system plays a pivotal role in the immune response to viral infections, mediating the presentation of viral peptides to T cells and influencing both the strength and specificity of the host immune response. Variations in HLA genotypes across individuals lead to differences in susceptibility to viral infection and severity of illness. This study uses observations from the early phase of the COVID-19 pandemic to explore how specific HLA class I molecules affect clinical responses to SARS-CoV-2 infection. By analyzing paired high-resolution HLA types and viral genomic sequences from 60 patients, we assess the relationship between predicted HLA class I peptide binding repertoires and infection severity as measured by the sequential organ failure assessment score. This approach leverages functional convergence across HLA-C alleles to identify relationships that may otherwise be inaccessible due to allelic diversity and limitations in sample size. Surprisingly, our findings show that severely symptomatic infection in this cohort is associated with disproportionately abundant binding of SARS-CoV-2 structural and non-structural protein epitopes by patient HLA-C molecules. In addition, the extent of overlap between a given patient's predicted HLA-C and HLA-A peptide binding repertoires correlates with worse prognoses in this cohort. The findings highlight immunologic mechanisms linking HLA-C molecules with the human response to viral pathogens that warrant further investigation. [ABSTRACT FROM AUTHOR]

Immunopeptidomics is the area of knowledge focused on the study of peptides assembled in the major histocompatibility complex (MHC), or human leukocyte antigen (HLA) in humans, which could activate the immune response via specific and selective T cell recognition. Advances in high-sensitivity mass spectrometry have enabled the detailed identification and quantification of the immunopeptidome, significantly impacting fields like oncology, infections, and autoimmune diseases. Current immunopeptidomics approaches primarily focus on workflows to identify immunopeptides from HLA molecules, requiring the isolation of the HLA from relevant cells or tissues. Common critical steps in these workflows, such as cell lysis, HLA immunoenrichment, and peptide isolation, significantly influence outcomes. A systematic evaluation of these steps led to the creation of an 'Immunopeptidome Score' to enhance the reproducibility and robustness of these workflows. This score, derived from LC-MS/MS datasets (ProteomeXchange identifier PXD038165), in combination with available information from public databases, aids in optimizing the immunopeptidome characterization process. The 'Immunopeptidome Score' has been applied in a systematic analysis of protein extraction, HLA immunoprecipitation, and peptide recovery yields across several tumor cell lines enabling the selection of peptides with optimal features and, therefore, the identification of potential biomarker and therapeutic targets. [ABSTRACT FROM AUTHOR]

Aging is an exceptionally complex process that depends on genetic, environmental, and lifestyle factors. Previous studies within the International HLA and Immunogenetics Workshop (IHIWS) component "Immunogenetics of Ageing" showed that longevity is associated with positive selection of HLA-DRB1*11- and DRB1*16-associated haplotypes, shown to be protective against diseases. Within the 18th IHIWS, we aimed to investigate the relevance of telomere length for successful aging and its association with classical HLAs. In total 957 individuals from Bulgaria, Turkey, Romania, and Poland in two age groups, elderly individuals (age 65–99 years) and ethnically matched young group (age 18–64 years), were investigated. The obtained results confirmed interpopulation differences in the distribution of HLA alleles, documented the lengths of telomeres in analyzed populations, and demonstrated significant associations of telomere length with aging as well as with the presence of some HLA class I or class II alleles. They suggest that telomere length assessment combined with HLA genotyping may help identify immunogenetic profiles associated with longevity. The associations between HLA and telomeres support the theory that HLA genes influence the aging process. However, further research is needed to clarify the biological basis of the observed relationships. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the association between human leukocyte antigen (HLA) and paraneoplastic neurological syndromes (PNS) with Hu antibodies, and potential specificities according to clinical presentation and cancer status. Methods: HLA genotypes at four-digit resolution were imputed from available genome-wide association data. Allele carrier frequencies were compared between patients (whole cohort, n = 100, and according to clinical presentation and cancer status) and matched healthy controls (n = 508) using logistic regression controlled by the three main principal components. Results: The clinical presentation of 100 anti-Hu patients involved the central nervous system (28, 28%), the peripheral nervous system (36, 36%) or both combined (36, 36%). Cancer diagnosis was certain in 75 (75%). HLA association analyses revealed that anti-Hu PNS patients were more frequently carriers of DQA1*05:01 (39% vs. 19%, OR = 2.8 [1.74–4.49]), DQB1*02:01 (39% vs. 18%, OR = 2.88 [1.79–4.64]) and DRB1*03:01 (41% vs. 19%, OR = 2.92 [1.80–4.73]) than healthy controls. Remarkably, such DR3 ~ DQ2 association was absent in patients with pure central involvement, but more specific to those manifesting with peripheral involvement: DQA1*05:01 (OR = 3.12 [1.48–6.60]), DQB1*02:01 (OR = 3.35 [1.57–7.15]) and DRB1*03:01 (OR = 3.62 [1.64–7.97]); being even stronger in cases with sensory neuropathy, DQA1*05:01 (OR = 4.41 [1.89–10.33]), DQB1*02:01 (OR = 4.85 [2.04–11.53]) and DRB1*03:01 (OR = 5.79 [2.28–14.74]). Similarly, DR3 ~ DQ2 association was only observed in patients with cancer. Discussion: Patients with anti-Hu PNS show different HLA profiles according to clinical presentation and, probably, cancer status, suggesting pathophysiological differences. [ABSTRACT FROM AUTHOR]

Purpose: Sympathetic ophthalmia (SO) is considered as an autoimmune disease with unclear mechanisms. This study investigated the relationship between HLA polymorphisms and SO. Methods: HLA typing was performed using the LABType reverse SSO DNA typing method. The allele and haplotype frequencies were assessed using the PyPop software. Statistical significance of genotype distributions between 116 patients and 84 healthy individuals (control) was determined using Fisher's exact test or Pearson's chi-squared test. Results: The SO group had a higher frequency of HLA-DRB1 * 04:05, HLA-DQB1 * 04:01, DRB1 * 04:05-DQB1 * 04:01 haplotype as compared to the control group (Pc < 0.001 for all). Conclusion: This study revealed that DRB1 * 04:05 and DQB1 * 04:01 alleles, as well as DRB1 * 04:05-DQB1 * 04:01 haplotye could be potential risk factors for SO. [ABSTRACT FROM AUTHOR]

Objective is to examine the background of IAS and the variations in drugs that trigger it among patients who have been genetically tested, aiming to deepen our understanding of this condition. HLA Analysis of 68 cases showed that DR4 is predominant, especially in individuals of East Asian descent, notably in DRB1 *0406. Methimazole was the primary drug associated with IAS in these populations, while in Caucasian individuals, the emphasis was on DRB1 *0403, with lipoic acid being the common inducer. The key factor determining disease risk is the combination of chromosomal allele variations, with HLA class II allele DR4 positive patients showing a strong association with DQA1 *0301/DQB1 *0302. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has posed unprecedented global health challenges since its emergence in December 2019. The rapid availability of vaccines has been estimated to save millions of lives, but there is variation in how individuals respond to vaccines, influencing their effectiveness at an individual, and population level. This review focuses on human genetic factors influencing the immune response and effectiveness of vaccines, highlighting the importance of associations across the HLA locus. Genome-Wide Association Studies (GWAS) and other genetic association analyses have identified statistically significant associations between specific HLA alleles including HLA-DRB1*13, DBQ1*06, and A*03 impacting antibody responses and the risk of breakthrough infections post-vaccination. Relationships between these associations and potential mechanisms and links with risks of natural infection or disease are explored, and this review concludes by emphasizing how understanding the mechanisms of these genetic determinants may inform the development of tailored vaccination strategies. Although complex, we believe these findings from the SARS-CoV2 pandemic offer a unique opportunity to understand the relationships between HLA and infection and vaccine response, with a goal of optimizing individual protection against COVID-19 in the ongoing pandemic, and possibly influencing wider vaccine development in the future. [ABSTRACT FROM AUTHOR]

Los organismos reguladores, como la Food and Drug Administration (FDA) y la European Medicines Agency (EMA), reconocen la farmacogenética como una herramienta clave en sus guías farmacológicas para el asesoramiento farmacéutico. En este contexto, la farmacia comunitaria tiene un papel esencial al responder a esta necesidad asistencial, lo que podría traducirse en una mejora significativa en la calidad de vida de los pacientes al evitar tratamientos ineficaces o potencialmente contraindicados. En este trabajo, hemos llevado a cabo una revisión sistemática de la evidencia científica disponible sobre las interacciones entre fármacos y genes de interés para la farmacia comunitaria. Se han identificado los principales genes y polimorfismos relacionados con la respuesta y los efectos adversos a tratamientos comunes en atención primaria. Finalmente, proponemos un modelo para la implementación de servicios de farmacogenética en la farmacia comunitaria.

Background: Oxaliplatin is commonly used to treat gastrointestinal malignancies. However, its applications are limited due to potential adverse drug reactions (ADRs), particularly severe anaphylactic shock. There is no method to predict or prevent ADRs caused by oxaliplatin. Therefore, we aimed to investigate the genetic HLA predisposition and immune mechanism of oxaliplatin-induced ADRs. Methods: A retrospective review was performed for 154 patients with ADRs induced by oxaliplatin during 2016–2021 recorded in our ADR notification system. HLA genotyping was conducted for 47 patients with oxaliplatin-induced ADRs, 1100 general population controls, and 34 oxaliplatin-tolerant controls in 2019–2023. The in vitro basophil activation test (BAT) was performed and oxaliplatin-specific IgE levels were determined. Results: The incidence of oxaliplatin-induced ADRs and anaphylactic shock in our cohort was 7.1% and 0.15%, respectively. Of the 154 patients, 67.5% suffered rash/eruption; 26.0% of the patients who could not undergo oxaliplatin rechallenge were considered to show oxaliplatin-induced immune-mediated hypersensitivity reactions (HRs). The genetic study found that the HLA-DRB∗12:01 allele was associated with oxaliplatin-induced HRs compared to the general population controls (sensitivity = 42.9%; odds ratio [OR] = 3.4; 95% CI = 1.4–8.2; P = 0.008) and tolerant controls (OR = 12; 95% CI = 2.3–63.7; P = 0.001). The in vitro BAT showed higher activation of CD63+ basophils in patients with oxaliplatin-induced HRs compared to the tolerant controls (P

OBJECTIVES: Here, we report the distribution of HLA-DPB1 alleles studied in a cohort of 55 randomly collected blood samples from unrelated Taiwanese individuals and the deduced most likely HLA haplotypes associated with the defined DPB1 alleles in the cohort. Our aim is to reveal the unprecedented data on the distribution of HLA-DPB1 alleles in the Taiwanese population and to find out the most probable HLA haplotypes associated with the HLA-DPB1 alleles detected. MATERIALS AND METHODS: The material for this study was blood samples, preserved in K2EDTA and/or acid citrate dextrose anticoagulants. The blood donors were voluntary individuals of Tzu Chi Bone Marrow Donor Registry, Tzu Chi Stem Cells Center, Hualien Tzu Chi Hospital. Sequence-based typing of the Sanger’s sequencing method was performed for the HLA allelic typing. To discern the HLA-DPB1 alleles, exons 2 and 3 of the HLA-DPB1 locus were sequenced. Target exon sequence amplifications were achieved by polymerase chain reaction, and the resulting amplicons were sequenced by BigDye Terminator Cycle Sequencing Ready Reaction Kit according to the manufacturer’s protocols. Results: In the total number of 55 randomized unrelated Taiwanese individuals studied, we detected 11 different HLA-DPB1 alleles. DPB1*05:01 (44.54%) was the allele with the highest frequency observed and the next highest frequency allele found was DPB1*02:01 (17.27%), while DPB1*38:01 (0.90%) and DPB1*700:01N (0.90%) ranked the least observed DPB1 alleles. Conclusion: Our findings in this study may be useful in researches reinforcing the comprehensive understanding on the distribution of DPB1 alleles and their associated HLA haplotypes and their clinical applications in Taiwanese.

Abstract To investigate the genetic relationship between end stage renal disease (ESRD) and human leukocyte antigen (HLA) alleles in the Guangxi Zhuang population. We performed polymerase chain reaction reversed sequence-specific oligonucleotide (PCR-rSSO) in 325 patients with ESRD and genotyped the HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 loci. The direct counting method was used to determine the frequencies of HLA alleles, and Arlequin software (version 3.5.2.2) was used for haplotypic frequency analyses to compare the included ESRD patients with 350 healthy donors from the Guangxi Zhuang population. In our study, 120 HLA alleles, 284 HLA-A-B-DRB1 haplotypes, and 332 HLA-A-C-B-DRB1-DQB1 haplotypes were detected. We found that only A*11:01-B*15:02-DRB1*12:02 had a positive association with ESRD (P = 0.001, P c = 0.020, OR = 3.106, 95% CI = 1.497–6.446) after Bonferroni correction; thus, individuals with this haplotype may be susceptible to ESRD. A*11:01-B*15:02-DRB1*12:02 is a potentially valuable haplotype for evaluating the risk of ESRD in the Guangxi Zhuang population.

Type I diabetes susceptibility is caused by both environmental and genetic factors, the latter comprising approximately half of the total risk as evidenced by the fact that identical twins have approximately 50% concordance, suggesting 50% of the disease risk is environmental. The human leukocyte antigen (HLA) genes account for approximately half of the genetic risk, as demonstrated by the concordance between HLA identical siblings. Because environmental and genetic differences vary between racial groups, the incidence of type 1 diabetes (TID) differs across the world, being highest in Caucasians. Recent GWAS (genome-wide association studies) studies have suggested there may be up to 50 genomic regions contributing to the non-major histocompatibility complex (MHC) genetic risk contribution. This review presents and discusses the latest research on the MHC and non-MHC genes. Only the non-MHC regions, which have been confirmed in multiple studies and which are considered definite regions of genetic susceptibility, are included in the review.

Chronic lymphocytic leukemia (CLL) is a distinct category of lymphoproliferative disorder characterized by the clonal expansion of mature B cells, followed by their accumulation in primary and secondary lymphoid organs. Cluster of differentiation (CD) markers such as CD79b, CD45, CD23, CD22 and CD81 serve as reliable prognostic indicators in CLL as well as the human leukocyte antigen (HLA) with its well-documented associations with various cancers. This study aims to investigate, for the first time, potential connections between HLA typing and CD marker expression in CLL. Although it is one of the most prevalent neoplasms, there is a need for biomarkers that can improve survival. This study included 66 CLL patients and 100 controls, with all samples analyzed using biochemical methods, flow cytometry, and cytomorphology. Next-generation sequencing was performed for HLA typing. The results indicate that several CD markers are statistically associated with different HLA alleles, specifically CD45 with HLA-C*07:01:01; CD79b with HLA-DPA1*02:01:02; CD23 with HLA-B*39:01:01; CD22 with HLA-B*49:01:01, HLA-C*07:01:01, HLA-DPB1*02:01:02, and HLA-DRB1*07:01:01; and CD81 with HLA-DPB1*04:02:01, HLA-DQA1*01:04:01, and HLA-DQB1*05:03:01. In conclusion, this research demonstrates significant statistical links between HLA genes and immunophenotypic markers in CLL patients, shedding new light on the immunological context of CLL.

Abstract The Canary Islands inhabitants, a recently admixed population with significant North African genetic influence, has the highest incidence of childhood-onset type 1 diabetes (T1D) in Spain and one of the highest in Europe. HLA accounts for half of the genetic risk of T1D. Aims To characterize the classical HLA-DRB1 and HLA-DQB1 alleles in children from Gran Canaria with and without T1D. Methods We analyzed classic HLA-DRB1 and HLA-DQB1 alleles in childhood-onset T1D patients (n = 309) and control children without T1D (n = 222) from the island of Gran Canaria. We also analyzed the presence or absence of aspartic acid at position 57 in the HLA-DQB1 gene and arginine at position 52 in the HLA-DQA1 gene. Genotyping of classical HLA-DQB1 and HLA-DRB1 alleles was performed at two-digit resolution using Luminex technology. The chi-square test (or Fisher's exact test) and odds ratio (OR) were computed to assess differences in allele and genotype frequencies between patients and controls. Logistic regression analysis was also used. Results Mean age at diagnosis of T1D was 7.4 ± 3.6 years (46% female). Mean age of the controls was 7.6 ± 1.1 years (55% female). DRB1*03 (OR = 4.2; p = 2.13–13), DRB1*04 (OR = 6.6; p ≤ 2.00–16), DRB1* 07 (OR = 0.37; p = 9.73–06), DRB1*11 (OR = 0.17; p = 6.72–09), DRB1*12, DRB1*13 (OR = 0.38; p = 1.21–05), DRB1*14 (OR = 0.0; p = 0.0024), DRB1*15 (OR = 0.13; p = 7.78–07) and DRB1*16 (OR = 0.21; p = 0.003) exhibited significant differences in frequency between groups. Among the DQB1* alleles, DQB1*02 (OR: 2.3; p = 5.13–06), DQB1*03 (OR = 1.7; p = 1.89–03), DQB1*05 (OR = 0.64; p = 0.027) and DQB1*06 (OR = 0.19; p = 6.25–14) exhibited significant differences. A total of 58% of the studied HLA-DQB1 genes in our control population lacked aspartic acid at position 57. Conclusions In this population, the overall distributions of the HLA-DRB1 and HLA-DQB1 alleles are similar to those in other European populations. However, the frequency of the non-Asp-57 HLA-DQB1 molecules is greater than that in other populations with a lower incidence of T1D. Based on genetic, historical and epidemiological data, we propose that a common genetic background might help explain the elevated pediatric T1D incidence in the Canary Islands, North-Africa and middle eastern countries.

BACKGROUND: Type 1 diabetes mellitus (DM1) is a chronic autoimmune disease characterized by damage to insulin–producing cells of the pancreas, which eventually leads to the need for insulin replacement therapy. The clinical picture of DM1 is heterogeneous: the onset of the disease at an early age is characterized by a more acute manifestation and rapid depletion of residual insulin secretion. Variations of HLA genes can probably determine the clinical features of the course of DM1. To date, age-related features of HLA genes have been established in various populations, at the same time, such data are not available in the Russian population.AIM: To study the effect of HLA genes on predisposition to DM1 in preschool age.MATERIALS AND METHODS: A single-center, one-stage study, including data from 885 children (1 year — 18 years old) with previously diagnosed DM1 who are on intensified insulin therapy. The study participants’re divided into two groups: a group with a manifestation of DM1

The Zhejiang Han population, a subgroup of the Southern Han ethnic group, resides in Zhejiang Province, situated on the southeast coast of China. In this study, we conducted HLA genotyping for 813 voluntary umbilical cord blood donors from the Zhejiang Han population, targeting 11 HLA loci, namely HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DRB3/4/5, HLA-DQA1, HLA-DQB1, HLA-DPA1, and HLA-DPB1, using the next-generation sequencing method. Our analysis of the alleles and haplotypes revealed a high degree of polymorphism within these loci. A total of 289 unique HLA alleles were identified, with the HLA-B locus exhibiting the most significant diversity, while HLA-DRB4 displayed the lowest variation. Due to the inherent limitations of the sequencing method, some unresolvable alleles in the specific loci, such as HLA-DRB1, HLA-DPA1, and HLA-DPB1, were assigned as G group designation. In our comprehensive analysis across all 11 HLA loci, a total of 1204 haplotypes were estimated. The distribution of these alleles was similar to those of the Chinese Southern Han population while highly different from the Caucasian population. These findings contribute to a deeper understanding of the genetic characteristics of HLA loci within the Chinese Southern Han population. [ABSTRACT FROM AUTHOR]

Relevance. It is known that the immune response to the administration of immunobiological drugs is variable and depends on the individual characteristics of the organism. Host immunogenetic factors have a significant impact on the effectiveness of vaccination. In this study, the frequencies of alleles of the HLA class I (HLA-A, B, C) and class II genes (HLA-DRB1, DPB1, DQB1) were studied in groups of participants with different levels of antibodies (anti-HBs) after vaccination against viral hepatitis B. Aims of the work was to determine the possible relationship between alleles of HLA genes and the intensity of post-vaccination immunity against hepatitis B. Materials and methods. The study included 271 apparently healthy adults who were divided into 3 groups depending on the specific concentration of post-vaccination antibodies (anti-HBs) using ELISA. All calculations were made relative to the groups anti-HBs >100 mIU/ml (n=82), 10-100 mIU/ml (n=98) (protective antibody level) and anti-HBs